#include <vector>

using namespace std;

class Solution {
public:
    int fib(int n) {
        if (n == 0) {
            return 0;
        }
        vector<int> dp(n + 1);
        dp[1] = 1;
        for (int i = 2; i <= n; i++) {
            dp[i] = (dp[i - 1] + dp[i - 2]) % 1000000007;
        }
        return dp.back();
    }
};